The present invention can be applied to state-of-the-art vacuum brake power boosters as described, for example, in the Brake Handbook, 8th edition, Alfred Teves GmbH, herein incorporated by reference for its teachings in the field of brake systems. Specific reference to vacuum brake power boosters is found on pages 94 et seq. of this handbook.
The present invention also can be applied to brake systems which are equipped with anti-block and/or traction slip control. A pneumatic brake power booster for a brake system which has an anti-lock and/or traction slip control is described, for example, in German patent application No. P 3815768.3.
The aforesaid patent application discloses a pneumatic brake power booster, and in particular a vacuum brake power booster for a brake pressure control device. The patent specifically discloses an anti-block control device (ABS device) or a traction slip control device (TSC device) for automotive vehicles with a master cylinder, wheel cylinders, at least one pump for the positioning of at least one piston of the master cylinder, a pressure modulator which modulates the pressure in the wheel cylinders during the control modus, and an electronic controller which processes wheel sensor signals to actuating signals for the inlet valves and for the shut-off valves of the pressure modulator. The booster is comprised of a housing, a piston element, a diaphragm retainer in particular, and a diaphragm, preferably of a rolling diaphragm which sealingly connects the piston element to the housing and which permits movements of the piston element relative to the housing, the piston element being in active connection with the brake pedal.
It is proposed in the aforesaid German patent application that the housing, the piston element, in particular the diaphragm retainer, and the diaphragm preferably the rolling diaphragm, are configured as part of a travel switch for the control of the pump, in particular through the electronic controller.
It is shown by FIG. 4 of the German patent application that a travel sensor housing for a travel sensor 64 projects beyond the outer contour of the vacuum brake power booster.